title: Heat shock protein 90: role in enterovirus 71 entry and assembly and potential target for therapy.
abstract: Although several factors participating in enterovirus 71 (EV71) entry and replication had been reported, the precise mechanisms associated with these events are far from clear. In the present study, we showed that heat shock protein 90 (HSP90) is a key element associated with EV71 entry and replication in a human rhabdomyosarcoma of RD cells. Inhibition of HSP90 by pretreating host cells with HSP90β siRNA or blocking HSP90 with a HSP90-specific antibody or geldanamycin (GA), a specific inhibitor of HSP90, as well as recombinant HSP90β resulted in inhibiting viral entry and subsequent viral replication. Co-immunprecipitation of EV71 with recombinant HSP90β and colocalization of EV71-HSP90 in the cells demonstrated that HSP90 was physically associated with EV71 particles. HSP90 seems to mediate EV71 replication by preventing proteosomal degradation of the newly synthesized capsid proteins, but does not facilitate viral gene expression at transcriptional level. This was evident by post-treatment of host cells with GA, which did not affect the expression of viral transcripts but accelerated the degradation of viral capsid proteins and interfered with the formation of assembled virions. In vivo studies were carried out using human SCARB2-transgenic mice to evaluate the protection conferred by HSP90 inhibitor, 17-allyamino-17-demethoxygeldanamycin (17-AAG), an analog of geldanamycin, that elicited similar activity but with less toxicity. The results showed that the administration of 17-AAG twice conferred the resistance to hSCARB2 mice challenged with C2, C4, and B4 genotypes of EV71. Our data supports HSP90 plays an important role in EV71 infection. Targeting of HSP90 with clinically available drugs might provide a feasible therapeutic approach to treat EV71 infection.
authors.affiliation: Institute of Infectious Disease and Vaccinology, National Health Research Institutes, Zhunan Town, Miaoli, County, Taiwan ; Graduate Program of Biotechnology in Medicine, Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan.
authors.forename: Yueh-Liang
authors.initials: YL
authors.lastname: Tsou
authors.forename: Yi-Wen
authors.initials: YW
authors.lastname: Lin
authors.forename: Hsuen-Wen
authors.initials: HW
authors.lastname: Chang
authors.forename: Hsiang-Yin
authors.initials: HY
authors.lastname: Lin
authors.forename: Hsiao-Yun
authors.initials: HY
authors.lastname: Shao
authors.forename: Shu-Ling
authors.initials: SL
authors.lastname: Yu
authors.forename: Chia-Chyi
authors.initials: CC
authors.lastname: Liu
authors.forename: Ebenezer
authors.initials: E
authors.lastname: Chitra
authors.forename: Charles
authors.initials: C
authors.lastname: Sia
authors.forename: Yen-Hung
authors.initials: YH
authors.lastname: Chow
mesh_terms: D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D016227:Benzoquinones / Q000494:pharmacology*; D036022:Capsid Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D029821:Enterovirus A, Human / Q000187:drug effects* / Q000235:genetics / Q000472:pathogenicity; D004769:Enterovirus Infections / Q000188:drug therapy* / Q000235:genetics / Q000821:virology; D005786:Gene Expression Regulation; D018841:HSP90 Heat-Shock Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D054884:Host-Pathogen Interactions; D006801:Humans; D047029:Lactams, Macrocyclic / Q000494:pharmacology*; D051379:Mice; D008822:Mice, Transgenic; D058990:Molecular Targeted Therapy; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011485:Protein Binding; D059748:Proteolysis; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D014709:Vero Cells; D014771:Virion / Q000187:drug effects* / Q000235:genetics / Q000472:pathogenicity; D053586:Virus Internalization / Q000187:drug effects; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000906:Antibodies; D016227:Benzoquinones; D036022:Capsid Proteins; D018841:HSP90 Heat-Shock Proteins; D047029:Lactams, Macrocyclic; D034741:RNA, Small Interfering; C112765:tanespimycin; D046988:Proteasome Endopeptidase Complex